The higher up you are, the faster time passes - by bringing relativity back to Earth.
Past experiments have confirmed Albert Einstein's theory of relativity by comparing atomic clocks on the Earth's surface with ones placed in high-altitude jets and rockets.
But ABC Science reported on September 22 that Dr James Chin-Wen Chou and colleagues from the National Institute of Standards and Technology (NIST) in the US, have used the latest generation of atomic clocks to measure changes in time at a more down-to-Earth scale.
The researcher's first experiment involved lifting one clock above the other allowing them to measure the change in the Earth's gravitational pull over distances of less than a metre.
Their results confirmed time moves quicker, and hence a person ages faster, when they stand a couple of steps higher on a staircase.
The difference isn't much, about 25 billionths of a second over a 79 year life time, but it will have more practical applications in areas like global positioning systems and geophysics.
The key to both experiments is the quantum logic atomic clock, which uses the oscillation of a single aluminium ion to maintain precise timing. The atom vibrates between two energy levels allowing the clocks accuracy down to a second in 3.7 billion years.